► This experiment was conducted to determine the effects of corn silage hybrids and nonforage fiber sources (NFFS) in high forage diets formulated with high dietary…
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▼ This experiment was conducted to determine the effects of corn silage hybrids and nonforage fiber sources (NFFS) in high forage diets formulated with high dietary proportion of alfalfa hay (AH) and corn silage (CS) on ruminal fermentation and productive performance by early lactating dairy cows. Eight multiparous Holstein cows (4 ruminally fistulated) averaging 36 ± 6.2 d in milk were used in a duplicated 4 × 4 Latin square design experiment with a 2 × 2 factorial arrangement of treatments. Cows were fed 1 of 4 dietary treatments during each of the four 21-d periods. Treatments were: 1) conventional corn silage (CCS)-based diet without NFFS, 2) CCS-based diet with NFFS, 3) brown midrib corn silage (BMRCS)-based diet without NFFS, and 4) BMRCS-based diet with NFFS. Diets were isonitrogenous and isocaloric. Sources of NFFS consisted of ground soyhulls and pelleted beet pulp to replace a portion of AH and CS in the diets. In vitro 30-h NDF degradability was greater for BRMCS than CCS (42.3 vs. 31.2%). Neither CS hybrids nor NFFS affected intake of DM and nutrients. Digestibility of N, NDF, and ADF tended to be greater for cows consuming CCS-based diets. Milk yield was not influenced by CS hybrids and NFFS. However, a tendency for an interaction between CS hybrids and NFFS occurred with increasing milk yield due to feeding NFFS with the BMRCS-based diets. Yields of milk fat and 3.5% FCM decreased when feeding the BMRCS-based diet, and there was a tendency for an interaction between CS hybrids and NFFS by further decreased milk fat concentration because of feeding NFFS with BMRCS-based diet. Although feed efficiency (milk/DM intake) was not affected by corn silage hybrids and NFFS, there was an interaction between CS hybrids and NFFS because feed efficiency increased when NFFS was fed only with BMRCS-based diet. Total VFA production and individual molar proportion were not affected by diets. Dietary treatments did not influence ruminal pH profiles except that duration (h/d) of pH < 5.8 decreased when NFFS was fed in CCS-based diet but not in a BMRCS-based diet, causing a tendency for an interaction between CS hybrids and NFFS. Overall measurements in our study reveal that high forage NDF concentration (20% DM on average) may eliminate potentially positive effects of BMRCS. In the high forage diets, NFFS exerted limited effects on productive performance when they replaced AH and CS. Although the high quality AH provided adequate NDF (38.3% DM) for optimal rumen fermentative function, the low NDF concentration of the AH and the overall forage particle size reduced physically effective fiber and milk fat concentration.
Advisors/Committee Members: Allen J. Young.

► Due to loss of habitat, Gunnison sage-grouse (Centrocercus minimus) currently occupy 8.5% of their presumed historical range. One population survives in Utah, occurring in San…
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▼ Due to loss of habitat, Gunnison sage-grouse (Centrocercus minimus) currently occupy 8.5% of their presumed historical range. One population survives in Utah, occurring in San Juan County. The Gunnison Sage-grouse Rangewide Conservation Plan and the San Juan County Gunnison Sage-grouse Conservation Plan recommended management strategies to address identified conservation threats to the Utah population. I addressed three conservation strategies identified in the plans: 1) creation and enhancement of brood-rearing areas; 2) assessment of habitat conditions within the Gunnison Sage-grouse Conservation Area; and 3) prevention or reduction of perching events by avian predators on distribution line power poles.
From 2007-2009, I addressed the conservation strategy of creating mesic brood-rearing areas in Conservation Reserve Program fields and native sagebrush areas by evaluating the role of irrigation and dormant season cattle grazing on habitat. Vegetation and arthropod diversity in irrigated versus non-irrigated plots did not differ (p>0.01). Conservation Reserve Program plots exhibited greater arthropod abundance and cover of perennial grass than the native sagebrush plots, but lower diversity of perennial grasses and abundance and diversity of forbs (p<0.01).
The second conservation strategy I addressed was the completion of an assessment of habitat conditions within the Gunnison Sage-grouse Conservation Area. I measured vegetation conditions within habitat occupied and unoccupied by Gunnison sage-grouse. Cover and height of grasses exceeded guidelines for occupied and unoccupied habitats. Forb cover was below recommended guidelines in occupied habitat. Sagebrush cover was below guidelines for winter habitat. Habitat restoration efforts should focus on retaining existing sagebrush cover and establishment of sagebrush, forb, and grass cover within Conservation Reserve Program fields.
The third conservation strategy I evaluated was the retrofitting of distribution line power poles with perch deterrents to discourage avian predators from perching. I evaluated the efficacy of five perch deterrents. The perch deterrents did not mitigate potential avian predators from perching. A deterrent designed for insulators, in combination with physical deterrents we tested, has potential to prevent perching.
These studies provided a sound first step that can be built upon by the Monticello/Dove Creek Local Working Group to improve habitat conditions, reduce the threat of avian predation, and plan future conservation activities within the Conservation Area.
Advisors/Committee Members: Terry A. Messmer.

► The objective of this dissertation is to verify and explain the forward exchange rate unbiasedness hypothesis in the foreign exchange market. Since in most of…
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▼ The objective of this dissertation is to verify and explain the forward exchange rate unbiasedness hypothesis in the foreign exchange market. Since in most of the cases the unbiasedness hypothesis fails to hold, we try to provide three different explanations of this puzzling behavior in the three essays. The first essay tries to resolve the forward premium puzzle by addressing the model misspecification issue and thereby adding a time-varying risk premium term in the percentage change specification. The risk premium term is modeled using the GARCH-M representation and the model is estimated by applying a GARCH (1, 1) specification. The second essay attributes the failure of the unbiasedness hypothesis to hold to the nonstationarity of the spot and forward exchange rate. It verifies the existence of a cointegrating relationship between the spot and the forward exchange rates and thus specifies an Error Correction Model to better capture the relation between the spot and the forward rates. Further, a cointegrating or the existence of a long run relationship between the spot and forward exchange rates and the domestic and foreign interest rates is tested. It can be viewed as a robustness check where we ensure whether the cointegrated exchange rates are still related in the long run with the inclusion of the interest rates. The objective of the third essay is to apply the generalized method of moments (GMM) to test the unbiasedness hypothesis in the foreign exchange market. Empirical evidence suggests that the spot and forward rates are nonstationary with unit roots and are cointegrated. Cointegration further suggests that the changes in the spot rate can be modeled by an Error Correction Model. The third essay explicitly derives an ECM from the levels specification and uses the GMM estimation technique to test the unbiasedness hypothesis.
Advisors/Committee Members: Dr. Basudeb Biswas.

► We report changes in the intergranular material and grain morphology of YBa2Cu3O7-x during cyclic anneals between 780 and 980 ºC in oxygen at atmospheric pressure.…
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▼ We report changes in the intergranular material and grain morphology of YBa2Cu3O7-x during cyclic anneals between 780 and 980 ºC in oxygen at atmospheric pressure. Two endothermic reactions were detected: (a) the eutectic reaction of YBa2Cu3O7-x with CuO and BaCuO2 at 900 ºC (enthalpy ΔHa) and (b) the peritectic reaction of YBa2Cu3O7-x with CuO at 950 ºC (ΔHb). During the first anneal, only reaction (b) is detected, and although it should only occur if there is an excess of CuO, its signature is present in all published data. Cyclic annealing causes a monotonic decrease in ΔHb and an increase in ΔHa, larger average grain sizes, and greater volume fraction of the superconducting phase. A steady state is reached after 10 cycles at which point ΔHb = 0. We propose a model that explains the origin of the intergranular CuO and the changes in the intergranular material composition with cyclic annealing.
Advisors/Committee Members: Wilford N Hansen.

▼ An experimental demonstration of a new, non-contact particle characterization technique called Aerodynamic Vectoring Particle Sorting (AVPS) is presented. AVPS uses secondary blowing and suction control flows'flows that are a fraction of the jet flow rate'to sharply change the direction of a planar, particle-laden jet. As the jet is vectored, particles present in the flow experience a resultant drag force, dependent upon their size, that balances inertia. Since this balance determines the particle's trajectory, vectoring the flow leads to a separation of particles downstream. This simple, low-pressure-drop sorting technique classifies particles with less risk of damage or contamination than currently available sorting devices. AVPS is also shown to be capable of concentrating aerosols. Our measurements indicate that an air sample containing water-like particles can be concentrated by a factor of 10 using AVPS.
Advisors/Committee Members: Barton L Smith.

► Conflicts between humans and black bears (Ursus americanus) jeopardize the safety of both humans and bears, especially when bears become food-conditioned to anthropogenic food sources…
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▼ Conflicts between humans and black bears (Ursus americanus) jeopardize the safety of both humans and bears, especially when bears become food-conditioned to anthropogenic food sources in areas such as campgrounds. Interest in using non-lethal techniques, such as aversive conditioning, to manage such conflicts is growing. I conducted a captive experiment at The Wildlife Science Center in Minnesota and two field experiments in the La Sal Mountains, Utah, to investigate the effects of taste aversion conditioning using thiabendazole (TBZ) with a novel flavor cue and food removal on black bear food consumption and visitation to human food sources. In 2007, I conducted food trials with 6 captive black bears (3 control, 3 treatment). Controls received 1 kg baked goods scented with a peppermint-canola oil mixture and treatments received 1 kg baked goods also scented with a peppermint-canola oil mixture but mixed with 10-20 g TBZ. In the 2007 field experiment, I baited 24 field sites with 300 g of baked goods during a baseline phase for approximately 3 weeks. Half of these sites were then treated with 10 g of TBZ and camphor during a treatment phase for 4 weeks. In 2008, I baited 22 sites with 300 g of baked goods during a baseline phase for approximately 4 weeks. I then removed food and discontinued baiting at half of the sites for 4 weeks. Infrared cameras and barbed-wire hair snags were established at field sites to document bear visitation. I did not establish taste aversion in treated bears in captivity and bears fully consumed food in the majority of trials. Treating food supplies with 10 g TBZ and camphor flavor did not significantly reduce bear visitation (P = 0.615) or food consumption at field sites (P = 0.58). However, I observed a significant reduction in bear activity at sites where food was removed (P = 0.006). Potential reasons for my failure to reduce bear visitation using thiabendazole include insufficient conditioning, reluctance of bears to desist in investigating sites that previously contained untreated food, and masking of a treatment effect due to continued encounters of sites by new individuals.
Advisors/Committee Members: John A. Shivik.

► This dissertation attempts to provide a comprehensive examination on the non-market valuation of the effect of open space amenities and local public infrastructure on the…
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▼ This dissertation attempts to provide a comprehensive examination on the non-market valuation of the effect of open space amenities and local public infrastructure on the value of urban land and housing with both spatial heterogeneity and project heterogeneity. The demand for raw land is a derived demand for housing built on it. Therefore, we need to examine the land market and the housing market together. On the one hand, we estimate the value of urban land in a market that does not satisfy the usual assumptions of a competitive market structure as well as incentive incompatibility issues for transaction participants, with an application to a Chinese regional wholesale land market. These two violations to the traditional hedonic theory also generate two separate valuations on land with differentiated characteristics. On the other hand, we utilize the relative plane coordinates system, the three-dimensional distances, as well as the aggregate weight matrix, to implement the spatial hedonic estimation on the high-rise residential buildings in the same regional housing retail market in China. After these two steps, this dissertation, therefore, focuses on the profit maximization behavior of the property developer, which is the key role to link the factor market (i.e., the land market) and the commodity market (i.e., the housing market) together. Two methods are then employed to implement the hypothesis test on the hedonic price estimation including both inputs and outputs. First, a set of partial derivatives of the profit function with respect to various characteristics gives us the relationship between the marginal valuations in the land market and in the housing market. Second, we introduce a joint estimation approach that we call the spatial full information maximum likelihood (SFIML), which considers the land market, the housing market, and the property developer's profit maximization behavior all together in the estimation. Finally, we conduct a hypothesis test in both of these two scenarios to examine the validity of our linked markets assumption on the hedonic price estimation.
Advisors/Committee Members: Paul M. Jakus.

Liu, L. (2010). Three Essays on Environmental- and Spatial-Based Valuation of Urban Land and Housing. (Doctoral Dissertation). Utah State University. Retrieved from http://digitalcommons.usu.edu/etd/726

► Experiments were performed to investigate the effects of wash treatments, consisting of hot water, 2% lactic, 2% acetic, or 2% levulinic acid, for decontamination…
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▼ Experiments were performed to investigate the effects of wash treatments, consisting of hot water, 2% lactic, 2% acetic, or 2% levulinic acid, for decontamination of pathogenic bacteria previously inoculated onto meat surfaces, to inhibit growth of pathogenic bacteria inoculated onto previously washed meat surfaces, and on the organoleptic quality of sliced turkey roll and beef trim. Acid washes were no more effective at reducing Escherichia coli O157:H7 on beef plate, Listeria monocytogenes on sliced turkey roll, and Salmonella on pork belly than was water wash. Only lactic acid treatment was more effective than water at reducing Salmonella on chicken skin, but by less than 1 log CFU/cm2. Increasing wash temperatures with 2% levulinic acid did not reduce E. coli O157:H7 on beef plate. Organic acid washes did not protect against growth of L. monocytogenes and E. coli O157:H7. Acetic acid prevented growth of Salmonella, but only on chicken skin. Organic acid spray treatments of sliced turkey roll and beef trim did not affect consumer liking of turkey roll or cooked ground beef patties. Acid treatments had some effect on instrumental color measurements, but these appear to have little practical significance. Overall, washing with 2% organic acid solutions was no more effective at reducing pathogenic bacteria on meat surfaces than washing with water.
Advisors/Committee Members: Dr. Jeffery Broadbent.

► Wildlife managers have fed elk in North America for nearly 100 years. Giving winter feed to elk can compensate for a shortage of natural…
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▼ Wildlife managers have fed elk in North America for nearly 100 years. Giving winter feed to elk can compensate for a shortage of natural winter range and may boost elk populations while also helping prevent commingling with livestock and depredation of winter feed intended for livestock. In contrast to these benefits of supplemental feeding, there are economic and environmental costs associated with feeding, and elk herds that winter on feeding grounds have a higher risk of contracting and transmitting disease. Brucellosis is of primary concern now, and Chronic Wasting Disease may be in the future. Many see the discontinuation of winter-feeding programs as a necessary step for decreasing the risk of disease spread due to high animal densities associated with feeding during winter. My research evaluated the use of behavioral training to reduce reliance on supplemental winter feeding of elk, while minimizing population reductions and human-wildlife conflicts. My study was conducted at Deseret Land & Livestock (DLL) in Rich County, UT, where managers at DLL have over 20 years of data on elk feeding during winters of varying intensities. I tested the effectiveness of range improvements, strategic cattle grazing, dispersed supplemental feeding, hunting, and herding to distribute and hold elk in desired areas during winter. I compared elk numbers on the feed ground during this study with historic data on DLL, and also contrasted elk responses with other comparable feed sites in Wyoming that served as controls. In 2 mild winters we completely eliminated elk feeding without incident and were able to reduce the quantity and duration of feeding during 1 severe winter. Since the conclusion of my study, DLL has further reduced quantity and duration of feeding during severe winters, and has completely eliminated feeding in light winters. Based on a Before After Control Impact (BACI) analysis, the reduction in the proportion of the elk population fed at the study site was significantly less than the proportion of the elk populations fed at the control sites in Wyoming (P = 0.057). Based on these results, I anticipate wildlife managers can decrease dependence on costly supplemental winter feeding and reduce the risks of disease while keeping human-wildlife conflicts at a minimum. This research illustrates an adaptive method that can enable wildlife managers to keep elk populations in northern Utah at or near their current size, while constraining disease outbreak and transmission risks within "acceptable" levels.
Advisors/Committee Members: Frederick D. Provenza, PhD.

► This study was conducted to compare and contrast potential aroma compounds in the headspace and small molecule metabolites produced as a result of starter…
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▼ This study was conducted to compare and contrast potential aroma compounds in the headspace and small molecule metabolites produced as a result of starter culture metabolism in a full-fat and low-fat cheddar cheese model system. Past studies have indicated differences in the headspace flavor compound profiles between full-fat and low-fat Cheddar cheeses with no indication as to what compounds were produced as a result of starter culture metabolism.
Starter cultures were incubated in a Cheddar cheese extract environment that was made up of the water-soluble portion of Cheddar cheese with environmental conditions mimicking full-fat and low-fat Cheddar cheese by altering the levels of salt and milk fat globular membrane in the system. Incubation times were up to 14 days at 30°C and samples were taken at days 0, 1, 7, and 14. Headspace analysis was accomplished using solid phase micro-extraction coupled with GC-MS and small metabolites were monitored using metabolomic methods coupled with GC-MS.
Results indicate that the starter culture was responsible for an increase in the concentration of propan-2-one, heptan-2-one, 3-methylbutanal, heptanal, benzaldehyde, 2-ethylhexanal, and dimethyl trisulfide in both the full-fat and low-fat medias when compared to their respective controls. While heptanal was present at a higher concentration in the full-fat treatments compared to the low-fat treatments and 2- ethylhexan-1-ol and isothiocyanato cyclohexane were present at higher concentrations in the low-fat treatments compared to the full-fat treatments.
Principal component analysis for the headspace compounds showed a clear separation of the treatments with heptanal, p-cymene, nonan-2-one, and undecan-2-one contributing the most to the variation between the full-fat and low-fat samples, while 3- methylbutanal, heptan-2-one, benzaldehyde, 2-ethylhexan-1-ol, 2,6-dimethylheptan-4-ol, and 3-methylbutanol contributed the most to the variation between the controls and treatments.
The metabolomics data for both the bacteria and Cheddar cheese extract did not provide a clear separation between the full-fat and low-fat samples.
Advisors/Committee Members: Dr. Robert E. Ward.

Young MJ. Characterization of Volatile and Metabolite Compounds Produced by Lactococcus lactis in Low-Fat and Full-Fat Cheddar Cheese Extract. [Masters Thesis]. Utah State University; 2011. Available from: http://digitalcommons.usu.edu/etd/1029

► This study investigated the use of extrusion technology and fat replacers to produce high protein, low fat Cheddar cheese. In chapter 3, four different…
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▼ This study investigated the use of extrusion technology and fat replacers to produce high protein, low fat Cheddar cheese. In chapter 3, four different fat replacers were tested at the highest concentration level of each, as recommended by the manufacturers for low fat cheese, to investigate the change in cheese texture and optimize extruder conditions. In addition, the press time/pressure combinations of the extruded cheeses were optimized. The fat replacers and extruder conditions that were effective in improving the texture of low fat cheese were then used in chapter 4.
In chapter 4, three fat replacers were used at three different concentrations (lowest, middle and highest) as recommended by the manufacturers for replacing fat in cheese. The fat replacers were microcrystalline cellulose (MCC 1) (0.125%, 1.06% and 2%), whey protein concentrate (WPC 2) (0.50%, 0.75% and 1%) and whey protein concentrate (WPC 1) (0.40%, 2.20% and 4%). These fat replacers were effective in improving the texture of low fat cheese as determined from the results of chapter 3. The extruded cheese samples with and without fat replacers were analyzed for texture at three different time periods (1 day, 1 week, and 1 month). None of the fat replacers used were effective in improving the texture of low fat cheese significantly.
Since none of the treatments statistically improved the texture of low fat cheese, in the next part of the study, extrusion alone and WPC 1 at the middle concentration were then used to produce low fat cheese with high protein content by blending low moisture aged Cheddar cheese and nonfat cheese. Extrusion of cheese blends with or without fat replacer yielded cheese with high protein level. It was concluded from the study that the fat replacers we used were not effective in improving the texture but extrusion of aged Cheddar cheese with nonfat cheese can yield high protein cheese.
Advisors/Committee Members: Dr. Marie K. Walsh.

► This study focused on how African American couples in happy marriages talked about finances in their couple relationships. Qualitative methodology was used for this study,…
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▼ This study focused on how African American couples in happy marriages talked about finances in their couple relationships. Qualitative methodology was used for this study, and the data came from transcribed interviews with participants. Thirty-seven couples who identified their marriages as being strong, happy, or highly satisfying, volunteered to be interviewed for this study. All individual participants (74 total) talked about finances in their marriages, and all interviews were used for the purpose of this study. Their descriptions were coded and analyzed to explore the way that they talked about money issues in their marriages. The research questions focused on how couples talked about financial stress and how they talked about financial decisions in their relationships. An unanticipated finding was how they talked about transcending finances in their marriages. The findings can contribute to future research and financial education for African American couples.
Advisors/Committee Members: Linda Skogrand.

► Though there is ample evidence showing a positive relationship between a student's spatial ability and achievement in many fields of science, technology, and engineering, this…
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▼ Though there is ample evidence showing a positive relationship between a student's spatial ability and achievement in many fields of science, technology, and engineering, this study was seeking evidence that a relationship exists between a pre-engineering student's spatial ability and achievement in an electronics fundamentals course.
The importance of spatial ability to mentally design, develop, and manipulate images has been linked to measures of practical and mechanical abilities that are quite useful in technical occupations. Spatial abilities are frequently attributed to creative and higher order thinking skills in science and mathematics. Spatial imagery is tremendously important in art and creative thinking, and has an important role in abstract engineering disciplines such as electronics.
This study included 154 students enrolled in two sections of a fundamentals electronics course. The average age of the students enrolled in this course was 22.64 years old. The majority (89.6%) of the students was male, and 59.1% of the students majored in mechanical engineering. The average GPA of the participants was 3.4. The participants scored well on the spatial ability test (avg. 17.5, out of a possible 20), and the average grade received in the course was a B (avg. 85.6, out of a possible 100).
This study showed a highly significant (.000 alpha 1-tailed level) and near medium (Pearson's r of .29) correlation strength between spatial ability and achievement in the course. There was significant positive correlation between GPA and spatial ability – corroborating that pre-engineering students with high GPAs also have high spatial ability. When controlling for GPA in a partial correlation, it was found that spatial ability accounted for a significant amount of the variance in the semester scores, which suggests that spatial ability provides some good prediction of doing well in an electronics fundamentals course above and beyond what GPA predicts alone.
Many STEM subjects are at the atomic level and require using mental models that are created in the mind's eye and necessarily require spatial reasoning ability. The understanding of a given aspect of the physical world is best conceptualized with a mental model.
Advisors/Committee Members: Gary Stewardson.

► This dissertation focuses on how to design and employ networked unmanned vehicles for remote sensing and distributed control purposes in the current information-rich world. The…
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▼ This dissertation focuses on how to design and employ networked unmanned vehicles for remote sensing and distributed control
purposes in the current information-rich world. The target scenarios
are environmental or agricultural applications such as
river/reservoir surveillance, wind profiling measurement, and
monitoring/control of chemical leaks, etc. AggieAir, a small and
low-cost unmanned aircraft system, is designed based on the remote
sensing requirements from environmental monitoring missions. The
state estimation problem and the advanced lateral flight controller
design problem are further attacked focusing on the small unmanned
aerial vehicle (UAV) platform. Then the UAV-based remote sensing
problem is focused with further flight test results. Given the
measurements from unmanned vehicles, the actuation algorithms are
needed for missions like the diffusion control. A consensus-based
central Voronoi tessellation (CVT) algorithm is proposed for better
control of the diffusion process. Finally, the dissertation
conclusion and some new research suggestions are presented.
Advisors/Committee Members: Dr. YangQuan Chen.

► This study addressed a fundamental question in applied ecology and conservation; what is the predatory impact of introduced piscivorous sport fish on imperiled native fish…
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▼ This study addressed a fundamental question in applied ecology and conservation; what is the predatory impact of introduced piscivorous sport fish on imperiled native fish populations? More specifically, which of many introduced species and size-classes represent the greatest threats and should be targeted for control? In order to explore this important question, an integrated analysis of stable isotopes, quantified observed diet analysis, and stable isotope mass-balance models were used to quantify trophic interactions. These tools were used to construct food web models that were then compared to draw inferences regarding the relative contribution of prey fish, including rare native fish, to the diet of introduced sport fish. The stable isotope-derived food web illustrated a slight decoupling in energy flow between a pelagic and a benthic-littoral sub-web. The quantified diet analysis suggested piscivory was low overall, and that the introduced sport fish assemblage relied heavily on zooplankton and aquatic insect prey. The integrated stable isotope and quantified diet analysis demonstrated that the consumption of prey fish, particularly pelagic prey fish, was typically underestimated using stomach content analyses. From the evaluation, comparison, and integration of food web models, I suggest that substantial predation was occurring on the early life stages of Utah Lake fishes, including native fishes, and it was not being observed using stomach content analysis. My comparative modeling demonstrated that introduced sport fish are an impediment to native fish conservation and identified the small size-class of white bass as the most immediate threat.
Advisors/Committee Members: Todd Crowl.

► Accurate experimental oxygen mass transfer coefficient, a measure of how quickly oxygen travels from a gas bubble to the bulk liquid, is important for comparing…
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▼ Accurate experimental oxygen mass transfer coefficient, a measure of how quickly oxygen travels from a gas bubble to the bulk liquid, is important for comparing performance and for evaluating the oxygen transfer capability of a fermentor. Delays in probe response and changing gas volumes upon start-up of gassing affect the accuracy of oxygen transfer measurements. To mitigate these inaccuracies, a standard correction procedure for oxygen mass transfer data was established for highly oxygenated, well-mixed fermentation systems. Probe response time correction was generated by applying a second-order response model to dissolved oxygen probes and shown to be effective within 4%. By using a derived model for transient volume rise, the effect of changing gas volume at start-up was shown to cause very minimal error (1-2%) in kLa.
The unsteady-state method of kLa determination was used to compare design aspects of a hypothetical fermentor, including gas sparging devices and locations, baffle geometries and quantities, and impeller configurations. It was shown that locating the sparging device in the center of the tank, directly below the drive shaft and bottom impeller, is optimal for oxygen mass transfer. Sparger type was shown to have little effect on oxygen mass transfer values, although an open-pipe sparger was shown to provide slightly more oxygen mass transfer than a ring sparger. The use of rounded baffles in place of traditional rectangular baffles resulted in a 67-80% decrease in oxygen mass transfer coefficient. A comparison of three and four traditional baffles showed that three baffles produced a higher oxygen mass transfer than four. Correlation of baffle ratio and oxygen mass transfer coefficient indicated that the optimum baffle ratio is approximately one. Radial impellers were observed to provide better mixing, and thus higher oxygen mass transfer coefficients than axial impellers. In seven of ten comparisons, an impeller quantity ratio of 1.33 instead of 1.00 provided significant improvement in kLa. Additionally, only two of ten comparisons showed a difference between traditional Rushton turbine impellers and Smith turbine impellers, indicating that the difference in oxygen mass transfer capability of the two is negligible.
Advisors/Committee Members: Timothy Taylor.

Sorenson, K. L. (2010). Comparative Studies on Oxygen Mass Transfer for the Design and Development of a Single-Use Fermentor. (Masters Thesis). Utah State University. Retrieved from http://digitalcommons.usu.edu/etd/738

Chicago Manual of Style (16th Edition):

Sorenson, Kristan L. “Comparative Studies on Oxygen Mass Transfer for the Design and Development of a Single-Use Fermentor.” 2010. Masters Thesis, Utah State University. Accessed March 19, 2018.
http://digitalcommons.usu.edu/etd/738.

MLA Handbook (7th Edition):

Sorenson, Kristan L. “Comparative Studies on Oxygen Mass Transfer for the Design and Development of a Single-Use Fermentor.” 2010. Web. 19 Mar 2018.

Sorenson KL. Comparative Studies on Oxygen Mass Transfer for the Design and Development of a Single-Use Fermentor. [Masters Thesis]. Utah State University; 2010. Available from: http://digitalcommons.usu.edu/etd/738

Utah State University

17.
Rich, Melinda Snow.
"To Drink from Places": Uncovering a Rich Way of Life Near the Grand Canyon's North Rim.

► The chapters of this thesis focus on the history and stories of the people who built and traveled down the highways – Highway 89A, Highway 89,…
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▼ The chapters of this thesis focus on the history and stories of the people who built and traveled down the highways – Highway 89A, Highway 89, and Highway 67 – that branch out from the junction in front of Jacob Lake Inn, the Bowman/Rich family's 87-year-old lodge. The family's role in building roads, supporting and encouraging the growing tourist industry in Kanab and the North Rim of the Grand Canyon, and the converging effects of these choices have created the unique family culture and contributed to the history of the Grand Canyon region over time. Ultimately this thesis is about relationships, about the connections, influences, and choices of individuals, businesses, and government organizations that have created the myriad levels of local and national memory and unique distinctions between the tourist industry on the North and South Rims of the Grand Canyon that have framed my family's lifestyle at the junction to the National Park and surrounding scenic areas.
Advisors/Committee Members: Melody Graulich.

Rich, M. S. (2010). "To Drink from Places": Uncovering a Rich Way of Life Near the Grand Canyon's North Rim. (Masters Thesis). Utah State University. Retrieved from http://digitalcommons.usu.edu/etd/781

Chicago Manual of Style (16th Edition):

Rich, Melinda Snow. “"To Drink from Places": Uncovering a Rich Way of Life Near the Grand Canyon's North Rim.” 2010. Masters Thesis, Utah State University. Accessed March 19, 2018.
http://digitalcommons.usu.edu/etd/781.

MLA Handbook (7th Edition):

Rich, Melinda Snow. “"To Drink from Places": Uncovering a Rich Way of Life Near the Grand Canyon's North Rim.” 2010. Web. 19 Mar 2018.

Vancouver:

Rich MS. "To Drink from Places": Uncovering a Rich Way of Life Near the Grand Canyon's North Rim. [Internet] [Masters thesis]. Utah State University; 2010. [cited 2018 Mar 19].
Available from: http://digitalcommons.usu.edu/etd/781.

Council of Science Editors:

Rich MS. "To Drink from Places": Uncovering a Rich Way of Life Near the Grand Canyon's North Rim. [Masters Thesis]. Utah State University; 2010. Available from: http://digitalcommons.usu.edu/etd/781

► Online learning research is largely devoted to comparisons of the learning gains between face-to-face and distance students. While student learning is important, comparatively little is…
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▼ Online learning research is largely devoted to comparisons of the learning gains between face-to-face and distance students. While student learning is important, comparatively little is known about student satisfaction when engaged in online learning and what contributes to or promotes student satisfaction. Emerging research suggests there are a few strong predictors of student satisfaction, and other predictors that may or may not predict student satisfaction. None of the existing research examines predictors together, or statistically controls for course differences. This study examines the influence of various factors on student satisfaction including three types of interaction, Internet self-efficacy, and self-regulated learning.
Participants (N = 180) include both undergraduate and graduate students attending exclusively online classes in education. Students responded to an online survey adapted from several different scales. A pilot test of the survey and procedures showed strong validity and reliability for the sample. To control for course differences, data analysis focused on a hierarchical linear model (HLM) with student and class level variables. Results indicate learner-instructor interaction and learner-content interaction are significant predictors of student satisfaction when class-level variables are excluded. Of the class-level predictors, only the program from which the course was offered moderates the effect of learner-content interaction on student satisfaction. There is no direct impact of class-level predictors on student satisfaction. Learner-content interaction is the sole significant predictor when class-level predictors are added to the model. Supporting analyses for the HLM, results, limitations, and significance of the findings are reported and discussed.
Advisors/Committee Members: Andrew Walker.

► Although benefits of assistive technology (AT) to people with disabilities are widely apparent, barriers, primarily funding, still inhibit access to needed AT. All agencies receiving…
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▼ Although benefits of assistive technology (AT) to people with disabilities are widely apparent, barriers, primarily funding, still inhibit access to needed AT. All agencies receiving federal funding are required to show no discrimination with regard to age, race, disability, and gender. This case study of a state run agency providing funding for AT to enable independent living among people with disabilities involved analyzing spending data from 2003 2008 to determine who used the fund, what was purchased, and whether it was equitably distributed according to age, ethnicity, gender, and population density. Additionally variables predictive of amount spent per person were also sought. Results indicated the fund was equitably distributed according to ethnicity and gender, but not age and population density. Age, gender, population density, and device type were found to have main effects with an interaction between device type and primary cause of disability in predicting the amount spent per person.
(210 pages)
Advisors/Committee Members: Kerstin E. E. Schroder.

► ABSTRACT Predicting On-the-Job Teacher Success Based on a Group Assessment Procedure Used for Admission to Teacher Education by LaVaun Gene Faulk, Doctor of Education Utah…
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▼ ABSTRACT Predicting On-the-Job Teacher Success Based on a Group Assessment Procedure Used for Admission to Teacher Education by LaVaun Gene Faulk, Doctor of Education Utah State University, 2008 Major Professor: Deborah Byrnes, Ph.D. Department: Elementary Education Students who have graduated in Elementary Education at Utah State University, since 1997 when the group assessment interview procedure was adopted, and have been employed as teachers for at least two years were contacted. Students were located with the help of the Utah State Office of Education (USOE) and the Office of Teacher Education, Graduation, and Educator Licensing at USU. Permission to interview each teacher’s supervisor was obtained from each study participant. Principals were contacted and interview dates set. A self-anchoring interview was conducted to provide quantitative data on the success of each teacher. This new data was then used to compare each participant’s success as seen by supervisors to existing data already on record at USU. Specifically, principal interview data were compared to the participant’s student teaching scores, prior academic achievement data (grade point average and American College Test scores), and ratings the teacher received on the group assessment interviews when applying to the elementary education teacher training program at USU. (107 pages)
Advisors/Committee Members: Deborah Byrnes.

Faulk, L. G. (2008). Predicting On-The-Job Teacher Success Based On A Group Assessment Procedure Used For Admission To Teacher Education. (Doctoral Dissertation). Utah State University. Retrieved from http://digitalcommons.usu.edu/etd/78

Chicago Manual of Style (16th Edition):

Faulk, LaVaun Gene. “Predicting On-The-Job Teacher Success Based On A Group Assessment Procedure Used For Admission To Teacher Education.” 2008. Doctoral Dissertation, Utah State University. Accessed March 19, 2018.
http://digitalcommons.usu.edu/etd/78.

Faulk LG. Predicting On-The-Job Teacher Success Based On A Group Assessment Procedure Used For Admission To Teacher Education. [Doctoral Dissertation]. Utah State University; 2008. Available from: http://digitalcommons.usu.edu/etd/78

Utah State University

21.
Hooker, Toby D.Consequences of Vegetation Change on the Dynamics of Labile Organic Matter and Soil Nitrogen Cycling in a Semiarid Ecosystem.

► Sagebrush-dominated ecosystems are being transformed by wildfire, rangeland improvement techniques, and exotic plant invasions. These disturbances have substantial effects on the composition and structure…
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▼ Sagebrush-dominated ecosystems are being transformed by wildfire, rangeland improvement techniques, and exotic plant invasions. These disturbances have substantial effects on the composition and structure of native vegetation, but the effects on ecosystem C and N dynamics are poorly understood. To examine whether differences in dominant vegetation affect the quantity and quality of plant organic matter inputs to soil, ecosystem C and N pools and rates of plant turnover were compared among historically grazed Wyoming big sagebrush, introduced perennial crested wheatgrass, and invasive annual cheatgrass communities. Since low soil moisture during the summer may inhibit the microbial colonization of plant detrital inputs and result in C-limitations to microbial growth, soils were treated with an in situ pulse of plant detritus prior to the onset of the summer dry-season, and rates of soil C and gross N cycling were compared between treated and untreated soils. Finally, because plant detritus is the dominant form of labile C input to soil microbes over a large portion of the year, the decomposition of 13C-labeled annual grass detritus was used to determine the importance of plant detritus versus soil organic matter as microbial substrate. Results revealed large differences in ecosystem C and N pools, and in the quantity of plant C and N inputs to soil among vegetation types, but differences in soil C and N cycling rates were more subtle. Plant biomass pools were greatest for sagebrush stands, but plant C and N inputs to soil were greatest in cheatgrass communities, such that rates of plant C and N turnover appeared to be accelerated in disturbed ecosystems. Earlier release of plant biomass to soil detrital pools stimulated N availability to a greater extent than C availability relative to untreated soils, and this effect could not be predicted from the C:N stoichiometry of plant detritus. Finally, in situ decomposition of cheatgrass detritus was rapid; however, there was no clear evidence of a time-lag during summer in microbial colonization of recently released plant detritus, and microbial consumption of plant detritus did not result in N-limitations to microbial growth.
Advisors/Committee Members: John M Stark.

► Gray wolf (Canis lupus) depredation on beef calves has been studied extensively in recent years. As wolf populations increase throughout the United States there is…
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▼ Gray wolf (Canis lupus) depredation on beef calves has been studied extensively in recent years. As wolf populations increase throughout the United States there is a corresponding increase in wolf/livestock interactions. Most research concentrates on summaries of reported depredations and surveys of producers affected by depredations. The objective of this study was to present data on the fate of beef calves on 3 farms in Minnesota and Wisconsin over a 2-year period. Predator presence/absence was studied as an indicator of potential depredations. Also, data are presented comparing 2 techniques that may aid researchers and livestock producers with monitoring livestock. Radio telemetry collars and ear tags were applied to beef calves on 3 farms in northern Minnesota and Wisconsin during the spring and summer of 2006 and 2007. During this time, 4 calves were killed by wolves on the study farms. Wolves did not appear to be selecting the youngest calves and most depredations occurred from April through July. Although not statistically significant, wolf sign appeared at slightly higher rates on study farms than on land adjacent to these farms. Predator sign, including coyote (Canis latrans) and black bear (Ursus americanus), appeared more often in the heavily forested areas of the farms. Radio collars and radio ear tags were helpful for monitoring beef calves during this study. Radio collars had much longer transmitting distances than ear tags (2.3 ± 0.8 miles and 0.4 ± 0.2 miles, respectively). Radio ear tags had a potential for causing beef calves' ears to droop or were ripped out, possibly lowering their market value. Currently, cost is prohibitive for the widespread use of radio transmitters for monitoring livestock but as the price of new technologies decreases, transmitters may become an integral part of livestock production on farms with chronic wolf depredation.
Advisors/Committee Members: John A. Shivik.

▼ Monitoring population trend and estimating vital demographic parameters are essential for effective management of a mule deer (Odocoileus hemionus) population. Because of financial constraints, many wildlife agencies use computer models to obtain indirect indices of population size and trend as an alternative to annual field-based estimates of population size. These models are based primarily on herd composition counts and harvest rates from hunter-harvest surveys, and are rarely field validated. I developed an alternative method for monitoring population dynamics of wintering populations of mule deer. I designed a hybrid monitoring program that combined annual vital rate monitoring to track changes in population growth rate with a field-based approach for estimating population abundance. The program allocated resources optimally towards the most critical components of mule deer population dynamics, and consisted of 4 field surveys: annual monitoring of age ratios, overwinter fawn survival, and annual doe survival, with field-based estimates of population size only once every 4 years. Surveys were conducted from 2006 to 2008 in Wildlife Management Unit (WMU) 2, Utah, and cost $29,298 per year, prorated over 4 years. Unfortunately, financial constraints prohibit the implementation of this monitoring program in every WMU in Utah. Instead, the program can be implemented in select WMUs throughout the state, with survival data collected in these core units, providing estimates for nearby satellite units. To establish core-satellite unit pairs, I developed a proxy method for determining correlation in survival rates between core and satellite units using model-simulated estimates. I demonstrated this core-satellite method using WMU 2 as a core and WMU 3, an adjacent unit, as a satellite. Finally, I compared a multiple data sources (MDS) model with a herd composition-based population model, POP-II. The MDS model better approximated observed data, and provided statistical rigor. Overall, the hybrid program was less costly and provided more precise estimates of population trend than could be achieved with a monitoring program focused on abundance alone, and was more defensible than herd composition monitoring. After establishing correlations in doe and fawn survival between core and satellite units, data collected in core units via the hybrid program could then be used to model the mule deer population dynamics of other units using MDS modeling procedures. This combined approach could be an effective statewide program for monitoring mule deer populations.
Advisors/Committee Members: Mary M. Conner.

Bernales, H. H. (2010). Development of an Innovative Statewide Population Monitoring Program for Mule Deer. (Masters Thesis). Utah State University. Retrieved from http://digitalcommons.usu.edu/etd/639

► The United States’ Endangered Species Act of 1973 has been recognized as one of the most powerful laws enacted to protect endangered species in the…
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▼ The United States’ Endangered Species Act of 1973 has been recognized as one of the most powerful laws enacted to protect endangered species in the world. Its protections for animal species extends onto private land, which has in some cases created conflict between the law, its enforcers, and private landowners. The Candidate Conservation Agreements with Assurances (CCAA) program was developed in 1999 to provide a regulatory incentive for private landowners to engage in pro-active conservation for sensitive species to preclude the need for listing under the ESA in the future. Since 1999, however, there have only been 17 CCAAs signed, a relatively small number given the thousands of species eligible for the program across the U.S. This research used semi-structured qualitative interviews with individuals from four participant categories to expand our understanding of why landowners might choose to participate in the CCAA program, and of what benefits and barriers they perceive in program implementation. Participant categories included 1) private landowners enrolled in a CCAA; 2) private landowners that are eligible to enroll, but declined to participate; 3) State fish and wildlife agency employees who have participated in CCAAs across the county; and 4) Fish and Wildlife Service employees responsible for CCAA program implementation. Twenty-six interviews were completed during this research project. Results suggest that program implementation is affected by a multitude of factors; no exclusive drivers were identified. However, the variety of factors that were identified are assessed and management and policy recommendations are made. Hopefully these results and recommendations can potentially affect program policy to increase participation and the potential of the CCAA program as an effective tool for conservation on private lands in the United States.
Advisors/Committee Members: Steven E Daniels.

► Determining the root uptake of xenobiotic organic chemicals into plants is critical for assessing the human and ecological health risks associated with the consumption of…
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▼ Determining the root uptake of xenobiotic organic chemicals into plants is critical for assessing the human and ecological health risks associated with the consumption of plants growing in contaminated environments. Root uptake of xenobiotic organics occurs passively in conjunction with transpiration and the transport from root to shoot is ultimately controlled by passage through one or more lipid root membranes. The transpiration stream concentration factor (TSCF), the ratio between the concentration of a chemical in the xylem to that in the solution used by the roots, is used to describe the relative ability of an organic chemical to be passively transported from root to shoot. However, relatively few experimental TSCF values exist due to the cost and the lack of regulatory requirements for generating such data. Where literature data exist for chemicals having more than one TSCF, the variability is often large due to the lack of standardized methods and difficulty in accounting for metabolism and volatilization losses occurring during the uptake experiments. Because of the scarcity of experimental values, estimated TSCFs are often used. Widely cited estimation approaches relating TSCF and the logarithm octanol/water partition coefficient (log KOW) suggest that only compounds that are in the intermediate lipophilicity range (log KOW = 2) will be taken up and translocated by plants. However, recent data for highly water soluble compounds such as 1,4-dioxane, MTBE, and sulfolane suggest that these estimation techniques should be critically reviewed. To re-evaluate the relationship between TSCF and log Kow, TSCFs were measured for 25 organic chemicals ranging in log KOW from -0.8 to 5 using an improved pressure chamber technique. The technique provides an approach for efficiently generating consistent plant uptake data. By using this data, a new mass transfer model relating TSCF and log KOW was developed that indicates that neutral, polar organic compounds are most likely taken up by plant roots and translocated to shoot tissue. An extensive review of literature TSCF studies supports the updated model.
Advisors/Committee Members: William Doucette.

► Regulated deficit irrigation (RDI) is the strategy of reducing irrigation rates during a specific period of growth and development, with the objective of conserving water…
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▼ Regulated deficit irrigation (RDI) is the strategy of reducing irrigation rates during a specific period of growth and development, with the objective of conserving water and managing plant growth while maintaining or improving yield and fruit quality. Mature tart cherry (Prunus cerasus L. 'Montmorency') trees in a commercial orchard were subjected to a range of irrigation deficits from pit hardening to harvest during the 2007 and 2008 seasons. Irrigation treatments replaced from 62% to 96% of ETc, during that period. Midday stem water potential measurements were significantly different among treatments before harvest. However, fresh weight yield at harvest did not differ significantly among irrigation treatments in either year (P-value=0.64). In 2008 the amount of undersized fruit eliminated during packout was significantly higher in the treatments replacing 61% and 68% of ETc than in the control (P-value<0.0001), but only amounted to 2.0% and 1.4% of total yields, respectively. This small increase in undersized fruit did not significantly affect packout. Fruit quality measurements, such as soluble solids concentration and chroma of whole intact fruit, increased with the severity of the irrigation deficit. Visible surface bark damage from mechanical harvesting appeared less severe as deficit levels increased. Return bloom was not significantly affected by irrigation treatments.
Advisors/Committee Members: Brent Black.

► High tunnels have been used successfully in many areas of the world to extend the growing season for numerous crops. However, very little research has…
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▼ High tunnels have been used successfully in many areas of the world to extend the growing season for numerous crops. However, very little research has been conducted to evaluate the season extension benefits offered by high tunnels to small fruit crops in high elevation growing areas such as the Intermountain West region of the United States. The use of high tunnels was investigated in North Logan, Utah (41.766 N latitude, 1405 m elevation, 119 freeze free days) to extend the growing season for both strawberries and raspberries. June-bearing `Chandler' strawberries in a fall-planted annual hill system were evaluated for early season production. High tunnels advanced spring strawberry production by approximately 3 weeks compared to field-grown plants. High tunnels were used for earlier planting and growth in a spring-planted day-neutral strawberry system. Day-neutral cultivars (`Albion', `Seascape', `Evie 2', and `Tribute') produced strawberries throughout the summer and into the fall with significantly higher yields from the high tunnel treatments than the field-grown plants. High tunnels also extended late-season strawberry production until mid-December. The floricane-fruiting red raspberry `Tulameen' was evaluated for early season production, and primocane-fruiting `Caroline' was evaluated for late season extension. High tunnels were unable to provide sufficient winter protection for the cold-tender `Tulameen' at this location. Results from late season extension indicated that high tunnels could extend late season raspberry production by as much as three weeks. However, peak yields for `Caroline' were before the first fall frost, and a later fruiting cultivar would be more suitable. In addition to research results, this thesis contains chapters on practical management considerations for commercial producers, and enterprise budgets to assist in evaluating the economic costs and returns of high tunnel strawberry and raspberry production.
Advisors/Committee Members: Brent L. Black.

► Most dams have a low-level outlet that consists of a closed conduit through the dam with a slide gate or valve to regulate flow.…
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▼ Most dams have a low-level outlet that consists of a closed conduit through the dam with a slide gate or valve to regulate flow. These outlets are used mainly for irrigational purposes but also for flushing the reservoir and controlling the reservoir elevation. When discharging through the low-level outlet works, negative pressures can develop on the downstream side of the gate creating a potential for cavitation damage and vibration. To minimize these effects, air vents (vented to the atmosphere) are installed on the downstream side of the gate to limit downstream pressure to something above vapor pressure (i.e., near atmospheric pressure).
Previous air venting studies have been mostly limited to large dam outlet geometries, which typically feature a vertical gate in a flat-bottomed discharge tunnel. The large-dam air demand analysis has been based on the Froude number of the supercritical flow at the vena contract (located between the gate and the hydraulic jump) and the water flow rate. Small to medium-sized embankment dams typically utilize a slide gate installed on the sloped upstream face for flow control, followed by a vertical elbow connected to a sloping pipe. With this outlet geometry, there is no 1-D vena contracta flow, no classical hydraulic jump, and no representative Froude number. Additionally, no head-discharge characteristic data have been found for inclined slide gates (vented or non-vented) for small to medium-sized dams. Consequently, unless a flow measurement structure is installed in the discharge channel downstream of the dam, determining the water discharge rate based on gate opening and head on the gate, and consequently the air demand is problematic. This study focuses on quantifying air demand and air vent sizing for the small to medium-sized embankment dam low-level outlet geometries by providing: 1. Cd values as a function of gate openings and air demand; to better estimate flow rates from outlet works of similar geometries. 2. Flow conditions for varying operating conditions. 3. A new relationship for sizing air vents as a function of driving head and gate opening. 4. The magnitude of negative pressures for non-vented conduits. 5. A foundation for future studies and development of air demand research. This thesis presents the findings of this study.
Advisors/Committee Members: Blake P. Tullis.

► Marx Creek, near Hyder in southeast Alaska, is a groundwater-fed, artificial salmon-spawning stream that was constructed to enhance the habitat of the atypically large chum…
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▼ Marx Creek, near Hyder in southeast Alaska, is a groundwater-fed, artificial salmon-spawning stream that was constructed to enhance the habitat of the atypically large chum salmon. The success of the upper Marx Creek has been limited primarily by the infiltration of silty water from the Salmon River through its flood-control dike, which results in a turbid stream environment that is not conducive to salmon spawning.
The purpose of this project was to determine whether baseflow from the groundwater system is sufficient to support a proposed 1,000-foot extension of Marx Creek. The extension would be constructed approximately 500 feet east of the existing channel, and would connect with the existing Marx Creek at a point downstream of the sediment-settling stream cell. The location of the new channel would prevent the turbid water from reaching the new channel, as it would flow into and settle out in the existing Marx Creek.
In order to accomplish this purpose, 20 monitoring wells were installed. Water level data were collected in each of the monitor wells. Slug and pumping tests were performed to determine the hydraulic conductivity at each of the well locations. Discharge measurements were also collected in July 2006 and July 2007. These data were used to create a three-dimensional groundwater flow model using Visual MODFLOW.
The model was calibrated to hydraulic head measurements and Marx Creek discharge. After achieving model calibration, three predictive simulations were run. In the first simulation the proposed extension was added to the calibrated model. The result was that baseflow to the extension significantly exceeded baseflow to Marx Creek, and that the addition of the proposed extension reduced baseflow to Marx Creek by 17%. In the second simulation, Marx Creek was removed from the model, while the proposed extension remained. The result was that discharge in the extension increased by 5%. In the third simulation a 1.06-foot drop in the model's hydraulic head was simulated, and the result was that discharge in the extension decreased by 18%. Based on these results, it is likely that baseflow to the proposed extension would be sufficient to provide habitat conducive to salmon spawning.
Advisors/Committee Members: Thomas E. Lachmar.

► This research examined teachers' online behaviors while using a digital library service – the Instructional Architect (IA) – through three consecutive studies. In the first two…
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▼ This research examined teachers' online behaviors while using a digital library service – the Instructional Architect (IA) – through three consecutive studies. In the first two studies, a statistical model called latent class analysis (LCA) was applied to cluster different groups of IA teachers according to their diverse online behaviors. The third study further examined relationships between teachers' demographic characteristics and their usage patterns. Several user clusters emerged from the LCA results of Study I. These clusters were named isolated islanders, lukewarm teachers, goal-oriented brokerswindow shoppers, key brokers, beneficiaries, classroom practitioners, and dedicated sticky users. In Study II, a cleaning process was applied to the clusters discovered in Study I to further refine distinct user groups. Results revealed three clusters, key brokers, insular classroom practitioners, and ineffective islanders. In Study III, the integration of teacher demographic profiles with clustering results revealed that teaching experience and technology knowledge affected teachers' effectiveness in using the IA. The implication, contributions, and limitation of this research are discussed.
Advisors/Committee Members: Mimi Recker.